Welcome to the forum, nice to have another international member
There are a few members now from Australia - although I'm not sure how close to Sydney they are
With regards a new wheel - there is a trader on here [MENTION=1597]Steve@EdgeAutomotive[/MENTION] that does re-trims of wheels, although they are UK based. You could try them but postage could be dear!
Ktec are probably the most well known of the RS specialists.
No one in OZ can map your car so you have to bite the bullet & get a remote tune from the UK.
A remap is the last thing you want to do if your planning other engine mods.